IIRC, in that Delucia vs. Gracie fight, I think Jason referred to his style as Kung Fu (he was certainly wearing that type of uniform in his pre-fight intro and was wearing a sash typical of the Kung Fu uniforms I've seen, in his actual fight.)

I only remember maybe one or two fighters very early in the UFC's history (sometime between UFC 1 and maybe...5 or 6) who ever claimed their style as Aikido.